Joseph Gordon-Levitt's 50/50 comfort

A teenage hustler and a young man obsessed with alien abductions cross paths, together discovering a horrible, liberating truth. Joseph Gordon-Levitt & Brady Corbet are in the lead roles of Neil McCormick and Brian Lackey, respectively with Chase Ellison and George Webster portraying the 8-year-old versions of their characters. Also starring Elisabeth Shue and Michelle Trachtenberg.

Joseph Gordon-Levitt only felt comfortable on '50/50' four days into filming.

The actor was a last minute replacement for James McAvoy on the comedy drama, and although he never felt pressure to put on a similar to performance to the Scottish star - who had worked on it for four days - he did want to make sure he beat his time on set.

He said: "A movie takes such a long time to put together and plan, and once it's in production, if something like that happens, it's a nightmare. Seth Rogen called me in dire straits and asked if I would look at the script, and I was a fan of his so I did.

"But I do remember, once we got past the fourth day I was like, 'OK, now I've done more than James had done.' "

Discussing his career, the US star admits most of it is down to luck and the trust of a small number of filmmakers.

He told G2: "I'm sure luck has a lot to do with it, and I wouldn't deny that. For a while after 'Third Rock From The Sun' no one wanted to hire me to do anything but a TV show, and I didn't really want to do that again. I'm grateful to a few filmmakers who took a chance on me, like Gregg Araki, who made 'Mysterious Skin' or Rian Johnson, who made 'Brick'.

"These are guys who were able to see I could play these other roles. I really owe them all my subsequent opportunities."